Ventilator with integrated blower to provide negative or positive pressure in a ventilator system

ABSTRACT

A ventilator system and method for medical use includes an integrated blower. The ventilator system may include an inspiration port for connection to an inspiratory limb of a dual-limb patient circuit, and an expiration port for connection to an expiratory limb of the dual-limb patient circuit. The system also includes a gas delivery device connected to the inspiration port to supply a pressurized flow of gas to the inspiration port to generate a positive pressure, and a blower having an inlet that is operatively connected to the expiration port and configured to be controlled to selectively supply a negative pressure level between 4 and 120 cmH 2 O to the expiration port. The system also includes an outlet to exhaust gas received from the expiration port. In another embodiment, the ventilator system includes a blower to generate positive pressure/flow to augment flow for noninvasive ventilation.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of prior U.S. patent application Ser. No.13/994,940, filed on Jun. 17, 2013, which is the National Stage ofInternational Application No. PCT/IB2011/055734, filed Dec. 16, 2011,which claims benefit of U.S. Provisional Application No. 61/425,493,filed Dec. 21, 2010.

TECHNICAL FIELD

This invention pertains to ventilators, and in particular, to aventilator including an integrated blower to provide negative orpositive pressure in a ventilator system.

BACKGROUND AND SUMMARY

Ventilators are used in a variety of settings. For example, in ahospital a patient may be ventilated as part of their medical care. Inparticular, ventilators are commonly provided in hospital intensive careunits (ICUs).

Many of these ventilators use high pressure or compressed gas source forbreath delivery. In addition to generating and delivering breaths to thepatient, a high-end ventilator may include an integrated systemimplementation. With such an implementation, a ventilator system caninclude other patient care modalities like secretion management and highfrequency ventilation etc. These modalities require both positivepressure and negative pressure in the system for effectiveimplementation. For example, in high frequency positive pressureventilation (HFPPV), positive pressure is generated from the highpressure, compressed, gas source and negative pressure is generated by aventuri system implementation.

For example, for an HFPPV implementation, the mean airway pressure (MAP)depends on the peak-to-peak amplitude of the positive pressure pulses.For higher frequencies or for higher amplitudes, the MAP may be too highfor the patient. MAP can only be lowered by applying negative pressureduring exhalation. This negative pressure may be generated by a venturieffect from the positive pressure side of the system. However, a venturisystem is very noisy and it has a relatively slow response. In anothermodality such as secretion management, a ventilator system needs todeliver insufflation (positive pressure) and exsufflation (negativepressure) to simulate a cough. In yet another modality such asnoninvasive ventilation incorporated in high-end ICU ventilators, ablower can additionally augment and/or provide higher flows of gas thatmay be needed for such ventilation therapy. The gas supplied fromindividual gas outlets in the hospitals may be limited to ˜180 litersper minute (lpm) and is adequate for the most invasive mechanicalventilation needs. However, for non-invasive ventilation, the ventilatorshould be able to generate much higher flows—on the order of 250 to 300liters/minute (lpm) to compensate for mask leaks.

Accordingly, it would be desirable to provide a ventilator and method ofventilation which can address one or more of these requirements.

In one aspect of the invention, a ventilator system comprises: aninspiration port configured to be connected to an inspiratory limb of adual-limb patient circuit, and an expiration port configured to beconnected to an expiratory limb of the dual-limb patient circuit; a gasdelivery device operatively connected to the inspiration port andconfigured to supply a pressurized flow of gas to the inspiration portto generate positive pressure; and a blower having an inlet that isoperatively connected to the expiration port and configured to becontrolled to selectively supply a negative pressure level between 4 and120 cmH₂O to the expiratory limb, and further having an outletconfigured to exhaust gas received via the expiration port.

In another aspect of the invention, a method of ventilation comprises:providing an inspiration port configured to be connected to aninspiration limb of a dual-limb patient circuit, and providing anexpiration port configured to be connected to an expiratory limb of thedual-limb patient circuit; supplying a pressurized flow of gas to theinspiration port to generate positive pressure; and selectivelyconnecting an inlet of a blower to the expiration port to selectivelysupply a negative pressure level between 4 and 120 cmH₂O to theexpiration port and to exhaust from an outlet of the blower gas receivedfrom the expiration port.

In yet another aspect of the invention, a ventilator system comprises: apatient circuit interface port configured to be connected to asingle-limb patient circuit; a gas delivery device operatively connectedto the patient circuit interface port and configured to supply apressurized flow of gas to the patient circuit interface port togenerate positive pressure; a blower having an outlet operativelyconnected to the patient circuit interface port and configured to supplya pressurized flow of air to the patient circuit interface port togenerate positive pressure; a pressure transducer configured to measurea patient airway pressure; at least one flow sensor configured tomeasure a gas flow in the patient circuit; and a controller configuredto control the gas delivery device and the blower in response to apressure transducer signal indicating the measured pressure in thepatient circuit and a flow sensor signal indicating the measured gasflow from the gas delivery device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a functional block diagram of a ventilator system thatincludes a blower to generate negative pressure in the system.

FIG. 2A is a detailed illustration of a first example embodiment of aventilator system that includes a blower, during a first phase of abreathing cycle.

FIG. 2B is a detailed illustration of the first example embodiment ofFIG. 2A, during a second phase of a breathing cycle.

FIG. 2C is a detailed illustration of the controller of FIG. 2A.

FIG. 3A is a detailed illustration of a second example embodiment of aventilator system that includes a blower, during a first phase of abreathing cycle.

FIG. 3B is a detailed illustration of the example of the second exampleembodiment of FIG. 3A, during a second phase of a breathing cycle.

FIG. 3C is a detailed illustration of the controller of FIG. 3A.

FIG. 4 is a detailed illustration of a third example embodiment of aventilator system for noninvasive ventilation that includes a blower.

DETAILED DESCRIPTION

The present invention will now be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsof the invention are shown. This invention may, however, be embodied indifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided asteaching examples of the invention.

FIG. 1 is a functional block diagram of a ventilator system 100.Ventilator system 100 includes a dual-limb patient circuit 110, a gasdelivery device 120, a blower 130, an exhalation valve 140 and acontroller 150.

Dual-limb patient circuit 110 includes an inspiratory limb 112, anexpiratory limb 114, a Y-connector 117, and a breathing tube 116connected to inspiratory limb 112 and expiratory limb 114 viaY-connector 117. In some embodiments, breathing tube 116 may be anendotracheal tube.

Gas delivery device 120 is a device configured to supply a pressurizedflow of gas to inspiratory limb 112 of dual-limb patient circuit 110 viainspiratory port 142 to generate positive pressure. Here, the gas may bea mixture of constituent gases, for example, air, oxygen, heliox, etc.In some embodiments, gas delivery device 120 is configured to receivepressurized gas from an external supply (e.g., a tank or through a walloutlet) and to control and/or regulate the flow of gas to patientcircuit 110. Gas delivery device 120 may include one or more valves andregulators.

Blower 130 has an inlet 132 which is configured in operation to receivegas from expiratory limb 114 of dual-limb patient circuit 110 via anexpiratory port 142, and further has an outlet 134 for exhausting gasreceived from expiratory limb 114. Here, a “blower” is defined as anyelectromechanical device that generates pressurized flow of gas byrotational movement of a surface(s) e.g. rotating blades and which canprovide a negative pressure of between 4 and 120 cmH₂O at its inlet 132.As example, a blower may comprise a rotating impeller or high speed fan.A blower leak port 135 is provided at the inlet side of blower 130.

Exhalation valve 140 operates to selectively connect inlet 132 of blower130 to expiratory port 142, for example during an exhalation phase of abreathing cycle, as will be discussed in greater detail with respect toFIGS. 2A-2C. Exhalation valve 140 is provided with a diaphragm 145.

In response to one or more input signals and/or programmed parameters,controller 150 controls blower 130 and exhalation valve 140 to provideventilation for a patient 10. For example, controller 130 may controlthe mean airway pressure in high frequency positive pressure ventilation(HFPPV) to maintain a target mean airway pressure as set by the user. Inanother example, for providing insufflation-exsufflation for secretionmanagement of the patient, controller 150 may control the patient airwaypressure during exsufflation.

The provision of blower 130 in ventilator 100 provides for severalpossible features and benefits in various operating modes. Some exampleembodiments will be explained with respect to the detailed illustrationsof FIGS. 2A-2C and 3A-3C, and FIG. 4.

FIGS. 2A-2C illustrate a first example embodiment of a ventilator wherean integrated blower may be used to generate negative pressure forcontrol of mean airway pressure (MAP) for HFPPV. In this case, in someembodiments the blower continuously generates low to moderate levels ofnegative pressure for the expiratory limb of a dual-limb patientcircuit.

FIG. 2A is a detailed illustration of a first example embodiment 200 ofa ventilator system during a first (inhalation) phase of a breathingcycle. Ventilator system 200 comprises a ventilator 205 with anintegrated blower 230, and a dual-limb patient circuit 210.

Ventilator 205 includes a gas delivery device 220, blower 230, anexhalation valve 240, and a controller 250.

Dual-limb patient circuit 210 includes an inspiratory limb 212, anexpiratory limb 214, a Y-connector 217, and a breathing tube connectedto inspiratory limb 212 and expiratory limb 214 via Y-connector 217. Insome embodiments, the breathing tube may be an endotracheal tube. Apressure transducer 215 is connected to Y-connector 217 for measuring apatient airway pressure provided to patient 10. Pressure transducer 215generates a measured patient airway pressure signal which is provided tocontroller 250.

Gas delivery device 220 is a device configured to supply a pressurizedflow of gas to inspiratory limb 212 of dual-limb patient circuit 210 viainspiratory port 222 to generate positive pressure. Here, the gas may bea mixture of constituent gases, for example, air, oxygen, heliox, etc.In some embodiments, gas delivery device 220 is configured to receivepressurized gas from an external supply (e.g., a tank or through a walloutlet) and to control and/or regulate the flow of gas to patientcircuit 210. Gas delivery device 220 may include one or more flowcontrol valves and/or regulators.

Blower 230 has an inlet 232 which is configured in operation to receivegas from expiratory limb 214 of dual-limb patient circuit 210 via anexpiratory port 242, and further has an outlet 234 for exhausting gasreceived from expiratory limb 214. A blower leak port 235 is provided atthe inlet side of blower 230.

As illustrated in FIG. 2A, in the first (inhalation) phase of thebreathing cycle, controller 250 controls exhalation valve 240 to closeoff a pathway from expiration limb 214 via expiratory port 242 to inlet232 of blower 230. In some embodiments controller 250 may turn off,reduce the speed, or reduce the blower-current for blower 230 during thefirst (inhalation) phase of the breathing cycle.

FIG. 2B is a detailed illustration of the second example embodimentventilator system 200 during a second (exhalation) phase of a breathingcycle. As can be seen in FIG. 2B, during the second (exhalation) phaseof the breathing cycle, controller 250 controls exhalation valve 240 toopen a pathway from expiratory port 242 to inlet 232 of blower 230, andcontrols blower 230 to operate to receive gas from expiration limb 214via expiratory port 242 at blower inlet 232 and to exhaust the gas fromblower outlet 234. In some embodiments, controller 250 provides a signalto blower 230 to vary or control the operating speed of blower 230 andthereby adjust or control the negative pressure supplied by blower 230.

FIG. 2C is a detailed illustration of controller 250 of FIG. 2A.Controller 250 receives a measured patient airway pressure, for examplefrom pressure transducer 215, and supplies output signals forcontrolling blower 230 and exhalation valve 240. In some embodiments,controller 250 calculates or determines a mean airway pressure (MAP)from the measured patient airway pressure signal, received for examplefrom transducer 215. In some embodiments, controller 250 provides theoutput signals for controlling blower 230 and exhalation valve 240 tomaintain the calculated MAP at or near a target MAP.

FIGS. 3A-3C illustrate a second example embodiment of a ventilatorsystem where an integrated blower may be used to generate negativepressure for exsufflation for secretion management for invasiveventilation. In some embodiments, the blower generates high levels ofnegative pressure for very brief durations at aninhalation-to-exhalation transition when the ventilator operates in asecretion management mode.

FIG. 3A is a detailed illustration of a second example embodiment 300 ofa ventilator system during a first (inhalation) phase of a breathingcycle. Ventilator system 300 comprises a ventilator 305 with anintegrated blower 330, and a dual-limb patient circuit 310.

Ventilator 305 includes a gas delivery device 320, blower 330, anexhalation valve 340, a controller 350, a two-way valve 360, and aventilator exhaust port 370. In some embodiments, the implementation ofthe two-way valve 360 may be integrated with the exhalation valve 340.

Dual-limb patient circuit 310 includes an inspiratory limb 312, anexpiratory limb 314, a Y-connector 317, and a breathing tube connectedto inspiratory limb 312 and expiratory limb 314 via Y-connector 317. Insome embodiments, the breathing tube may be an endotracheal tube. Apressure transducer 315 is used for measuring a patient airway pressureprovided to patient 10. Pressure transducer 315 generates a measuredpatient airway pressure signal which is provided to controller 350.

Gas delivery device 320 is a device configured to supply a pressurizedflow of gas to inspiratory limb 312 of dual-limb patient circuit 310 viainspiratory port 322 to generate positive pressure. Here, the gas may bea mixture of constituent gases, for example, air, oxygen, heliox, etc.In some embodiments, gas delivery device 320 is configured to receivepressurized gas from an external supply (e.g., a tank or through a walloutlet) and to control and/or regulate the flow of gas to patientcircuit 310. Gas delivery device 320 may include one or more flow valvesand/or regulators.

Blower 330 has an inlet 332 which is configured in operation to receivegas from expiratory limb 314 of dual-limb patient circuit 310 via anexpiratory port 342, and further has an outlet 334 for exhausting gasreceived from expiratory limb 314.

As illustrated in FIG. 3A, in the first (inhalation) phase of thebreathing cycle, controller 350 controls exhalation valve 340 to closeoff a pathway from expiration limb 314 via expiratory port 342 totwo-way valve 360. In some embodiments controller 350 may turn off,reduce the speed, or reduce blower-current for blower 330 during thefirst (inhalation) phase of the breathing cycle.

FIG. 3B is a detailed illustration of the second example embodimentventilator system 300 during a second (exhalation) phase of thebreathing cycle. As can be seen in FIG. 3B, during the second(exhalation) phase of the breathing cycle, controller 350 controlsexhalation valve 340 to open a pathway from expiratory port 344 totwo-way valve 360. Furthermore, in some embodiments, during anexsufflation period of an exhalation phase of a breathing cycle (e.g.,during an-inhalation-to-exhalation transition), controller 350 controlstwo-way valve 360 to connect inlet 332 of blower 330 to expiration limb314 via expiratory port 344, and controls blower 330 to exhaust gas fromblower outlet 334 to simulate cough to mobilize secretion. Also, duringa remainder of the exhalation phase of the breathing cycle, controller350 controls two-way valve 360 to connect ventilator exhaust port 370 toexpiration limb 314 via expiratory port 342. In some embodiments,controller 350 provides a signal to blower 330 to vary or control theoperating speed and supply current of blower 330 and thereby adjust orcontrol the negative pressure supplied by blower 330.

FIG. 3C is a detailed illustration of the controller 350 of FIG. 3A.Controller 350 receives a measured patient airway pressure signal, forexample from pressure transducer 315, and supplies output signals forcontrolling blower 330, exhalation valve 340, and two-way valve 360. Insome embodiments, controller 350 provides the output signals forcontrolling blower 330 and exhalation valve 340 to provide the targetexsufflation pressure and pressure during exhalation phase.

FIG. 4 is a detailed illustration of a third example embodiment of aventilator system where an integrated blower may be used to generatepositive pressure/flow to augment gas flow for noninvasive ventilation(NIV) where there may be limited flow of gas from a wall-outlet orcompressor, or limited gas flow through flow valves and/or regulators ofthe gas supply device of the ventilator system.

Ventilator system 400 comprises a ventilator 405 with an integratedblower 430, and a single-limb patient circuit 410.

Ventilator 405 includes: a gas delivery device including a pressurizedflow of gas 420 and one or more flow control valves 422 for oxygen andair; one or more air and oxygen flow sensors 424; a pressure reliefvalve 426; a pressure transducer 428; a blower 430 and an associatedone-way check valve 436; and a controller 450. Ventilator 405 includes apatient circuit interface port 442 for connection to patient circuit410. Ventilator 405 also includes a junction 407 for combining apressurized flow of gas (e.g., oxygen and/or air) from the gas deliverydevice, and a pressurized flow of air from blower 430 to generatepositive pressure.

Patient circuit 410 connects to a mask 20 for providing a pressurizedflow of gas to patient 10. Mask 20 may include a passive exhalation portor an active exhalation port.

In some embodiments, the pressurized flow of gas 420 is received from anexternal supply (e.g., a tank), for example through a wall outlet.

In operation, controller 450 controls the gas delivery device (e.g.,flow control valve(s) 422), blower 430, and pressure relief valve 426 inresponse to a patient airway pressure signal from pressure transducer428 indicating the measured patient airway pressure, and a flow sensorsignal from the one or more air and/or oxygen flow sensors 424indicating the measured gas flow from the gas delivery device. Blower430 supplements the flow supplied via the pressurized flow of gas 420,which is some cases may be limited, for example when ventilator 405 isconnected to gas supply via a wall outlet. In that case, in some casesthe gas flow from the pressurized flow of gas 420 may be limited toabout 180 liters/minute. In some embodiments, by means of thesupplemental flow of blower 430 via blower outlet 434, ventilator 405 iscapable of providing a gas flow rate on the order of 250 to 300liters/minute.

While preferred embodiments are disclosed herein, many variations arepossible which remain within the concept and scope of the invention.Such variations would become clear to one of ordinary skill in the artafter inspection of the specification, drawings and claims herein. Theinvention therefore is not to be restricted except within the scope ofthe appended claims.

What is claimed is:
 1. A ventilator system (100, 200, 300), comprising:an inspiration port (122, 222, 322) configured to be connected to aninspiratory limb (112, 212, 312) of a dual-limb patient circuit (110,210, 310), and an expiration port (142, 242, 342) configured to beconnected to an expiratory limb (114, 214, 314) of the dual-limb patientcircuit; a gas delivery device (120, 220, 320) operatively connected tothe inspiration port and configured to supply a pressurized flow of gasto the inspiration port to generate positive pressure; and a blower(130, 230, 330) having an inlet (132, 232, 332) that is operativelyconnected to the expiration port and configured to be controlled toselectively supply a negative pressure level between 4 and 120 cmH₂O tothe expiratory limb, and further having an outlet (134, 234, 334)configured to exhaust gas received via the expiration port.
 2. Theventilator system (100, 200, 300) of claim 1, further comprising anexhalation valve (140, 240, 340) configured to selectively connect anddisconnect the inlet of the blower from the expiration port.
 3. Theventilator system (100, 200, 300) of claim 2, further comprising: apressure transducer (115, 215, 315) configured to measure a patientairway pressure; and a controller (150, 250, 350) configured to receivea signal indicating the measured patient airway pressure and in responsethereto to control the exhalation valve to connect the blower inlet tothe expiration port during at least a portion of an exhalation phase ofa breathing cycle, and to disconnect the blower inlet from theexpiration port during an inspiration phase of a breathing cycle.
 4. Theventilator system (100, 200, 300) of claim 3, wherein the controller isfurther configured to control an operating speed and supply current ofthe blower.
 5. The ventilator system (300) of claim 4, furthercomprising: a ventilator exhaust port (370); and a two-way valve (360)having a valve input and first and second valve outputs, wherein thevalve input is connected to the expiration port, the first valve outputis connected to the blower inlet, and the second valve output isconnected to the ventilator exhaust port.
 6. The ventilator system (300)of claim 5, wherein the controller is configured to control the two-wayvalve to connect the blower inlet to the expiration port during anexsufflation period of the exhalation phase, and to connect theexhalation valve to the ventilator exhaust port after an exsufflationperiod of the exhalation phase.
 7. The ventilator system (300) of claim1, wherein the gas delivery device includes an inlet for receiving apressurized flow of gas and a valve for regulating delivery of thepressurized flow of gas to the patient circuit.
 8. The ventilator system(100, 200, 300) of claim 1, wherein the blower comprises a rotatingimpeller or a fan.
 9. A method of ventilation, comprising: providing aninspiration port (122, 222, 322) configured to be connected to aninspiration limb (112, 212, 312) of a dual-limb patient circuit (110,210, 310), and providing an expiration port (142, 242, 342) configuredto be connected to an expiratory limb (114, 214, 314) of the dual-limbpatient circuit; supplying a pressurized flow of gas to the inspirationport to generate positive pressure; and selectively connecting an inlet(132, 232, 332) of a blower (130, 230, 330) to the expiration port toselectively supply a negative pressure level between 4 and 120 cmH₂O tothe expiration port and to exhaust from an outlet (134, 234, 334) of theblower gas received from the expiration port.
 10. The method of claim 9,further comprising: measuring a patient airway pressure in the patientcircuit; and in response to the measured patient airway pressure,controlling an exhalation valve (140, 240, 340) to connect the blowerinlet to the expiration port during at least a portion of an exhalationphase of a breathing cycle, and to disconnect the blower from theexpiration port during an inspiration phase of a breathing cycle. 11.The method of claim 9, further comprising controlling an operating speedand current of the blower.
 12. The method of claim 9, further comprisingconnecting the blower inlet to the expiration port during anexsufflation period of an exhalation phase of a breathing cycle, andconnecting a ventilator exhaust port (370) to the expiration port afteran exsufflation period of the exhalation phase.
 13. The method of claim9, further comprising: receiving a pressurized gas supply from awall-outlet; and regulating the pressurized gas to supply thepressurized flow of gas to the inspiration port.